U.S. patent number 4,487,378 [Application Number 06/424,626] was granted by the patent office on 1984-12-11 for coreless toilet paper roll and method for manufacture thereof.
Invention is credited to Masashi Kobayashi.
United States Patent |
4,487,378 |
Kobayashi |
December 11, 1984 |
Coreless toilet paper roll and method for manufacture thereof
Abstract
A coreless toilet paper roll having a center hole with alternate
radial corners and inwardly bulged portions is manufactured by
winding toilet paper on a winding shaft having a polygonal or
gear-shaped section to form a roll on the winding shaft and then
extracting the winding shaft from the rod. The center hole produced
in this way is rigid and safe from collapse. The corners or gear
teeth of the winding shaft may be arranged helically on the winding
shaft to avoid noise during the winding. The toilet paper may be
moistened at the outset of winding to provide a more rigid center
hole.
Inventors: |
Kobayashi; Masashi (Nishimachi,
Fujinomiya-shi, Shizuoka-ken, JP) |
Family
ID: |
13795677 |
Appl.
No.: |
06/424,626 |
Filed: |
September 27, 1982 |
Foreign Application Priority Data
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May 19, 1982 [JP] |
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57-83200 |
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Current U.S.
Class: |
242/160.1;
242/520; 242/613.2 |
Current CPC
Class: |
A47K
10/16 (20130101); B26D 3/161 (20130101); B26D
7/01 (20130101); B65H 18/20 (20130101); B65H
18/28 (20130101); B65H 75/00 (20130101); B65H
75/10 (20130101); A47K 10/32 (20130101); B65H
2701/1846 (20130101); A47K 2010/3206 (20130101); B26D
2007/013 (20130101); B65H 2301/4148 (20130101); B65H
2301/41484 (20130101); B65H 2301/5133 (20130101); B65H
2404/43 (20130101); B65H 2701/18442 (20130101) |
Current International
Class: |
A47K
10/00 (20060101); A47K 10/16 (20060101); A47K
10/32 (20060101); A47K 10/24 (20060101); B65H
18/28 (20060101); B65H 18/20 (20060101); B65H
18/14 (20060101); B65H 18/00 (20060101); B65H
75/00 (20060101); B65H 75/04 (20060101); B65H
75/10 (20060101); B65H 017/00 () |
Field of
Search: |
;242/68,68.5,68.3,56R,56A,66,67.1R,56.2,56.3,1 |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
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426007 |
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Aug 1963 |
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JP |
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55-11100 |
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Jul 1979 |
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JP |
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54-43963 |
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Dec 1979 |
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JP |
|
Primary Examiner: Levy; Stuart S.
Assistant Examiner: Hail, III; Joseph J.
Attorney, Agent or Firm: Schwartz & Weinrieb
Claims
What is claimed is:
1. A coreless paper roll, comprising:
a roll of paper wherein the innermost plies of said roll of paper
define a substantially rigidified, non-collapsible aperture, having
a substantially polygonal cross-sectional configuration, capable of
removably accommodating a paper holder which can rotatably support
said coreless paper roll, and wherein further, all of said paper of
said paper roll, including said innermost plies of said roll of
paper which define said paper roll aperture, is capable of being
readily unrolled for a predetermined paper use,
said substantially polygonally shaped, substantially rigidified,
non-collapsible aperture being defined by means of
circumferentially arranged, alternatively disposed, radially
outwardly extending constrictions, and radially inwardly extending
bulged portions which have been partially collapsed radially
inwardly to a predetermined final extent.
2. The coreless paper roll according to claim 1, wherein the
constrictions of said aperture are acutely angled and the adjacent
bulged portions are in contact with one another.
3. The coreless paper roll according to claim 1 wherein the
constrictions of said aperture are arcuately divergent and the
adjacent bulged portions are separated from one another by said
constrictions.
4. A coreless paper roll as set forth in claim 1, wherein:
said roll of paper comprises toilet tissue.
5. A coreless paper roll as set forth in claim 1, wherein:
said aperture has an asterisk configuration.
6. A coreless paper roll as set forth in claim 1, wherein:
said aperture has a substantially hexagonal configuration.
7. A coreless paper roll as set forth in claim 1, wherein:
said aperture has a substantially square-shaped configuration.
8. A coreless paper roll as set forth in claim 1, wherein:
said aperture has a substantially pentagonal configuration.
9. A method for manufacturing a coreless paper roll comprising the
steps of:
mounting a winding shaft, having a polygonally shaped
cross-sectional configuration defined by alternative apex and
side-surface portions, upon a winding machine;
engaging a free end of said paper upon said winding shaft;
rotating said winding shaft so as to coil said paper over and about
said apex and side-surface portions of said winding shaft and
thereby form a coreless roll of paper wherein all of said paper of
said coreless paper roll, including the innermost plies of said
paper roll, is capable of being readily unrolled for a
predetermined paper use; and
removing said winding shaft from said roll of paper so as to permit
those portions of said paper roll initially in engagement with said
side-surface portions of said winding shaft to partially collapse
radially inwardly under the influence of centripetal force through
means of a predetermined final extent and thereby form radially
inwardly extending bulged portions, while those portions of said
paper initially in engagement with said apex portions of said
winding shaft simultaneously form radially outwardly extending
constrictions, whereby a substantially rigidified, non-collapsible
central aperture of said coreless paper roll is defined by said
innermost plies of said paper roll so as to be capable of removably
accommodating a paper roll holder.
10. A method for manfacturing a coreless paper roll as claimed in
claim 9, wherein during the winding of the paper, a riding roller
is used to apply to the roll of paper being wound a fixed pressure
as the thickness of the roll of paper increases.
11. A method of manufacturing a coreless paper roll as claimed in
claim 9, wherein the corners of the polygonal winding shaft are
parallel to the axis of the shaft.
12. A method for manufacturing a coreless paper roll as claimed in
claim 9, wherein the corners of the polygonal winding shaft are
helical with respect to the shaft, and at the completion of winding
the paper roll, the winding shaft is removed from the roll while
being rotated.
13. A method for manufacturing said coreless paper roll as set
forth in claim 9, wherein:
said paper roll comprises toilet tissue.
14. A method for manufacturing a coreless paper roll as set forth
in claim 9, wherein:
during the winding of the paper, a riding roller is used to apply
to the roll of paper being wound a pressure which decreases as the
thickness of the roll of paper increases.
15. A method for manufacturing a coreless paper roll comprising the
steps of:
mounting a winding shaft, having a gear-shaped cross-sectional
configuration defined by alternative teeth and groove portions,
upon a winding machine;
engaging a free end of said paper upon said winding shaft;
rotating said winding shaft so as to coil said paper over and about
said teeth and groove portions of said winding shaft and thereby
form a coreless roll of paper wherein all of said paper of said
coreless paper roll, including the innermost plies of said paper
roll, is capable of being readily unrolled for a predetermined
paper use; and
removing said winding shaft from said roll of paper so as to permit
those portions of said paper roll initially in engagement with said
groove portions of said winding shaft to partially collapse
radially inwardly under the influence of centripetal force through
means of a predetermined final extent and thereby form radially
inwardly extending bulged portions, while those portions of said
paper initially in engagement with said teeth portions of said
winding shaft simultaneously form radially outwardly extending
constrictions, whereby a substantially rigidified, non-collapsible
central aperture of said coreless paper roll is defined by said
innermost plies of said paper roll so as to be capable of removably
accommodating a paper roll holder.
16. A method for manufacturing a coreless paper roll as claimed in
claim 9 or 15, wherein when the paper is wound on said winding
shaft, the paper is moistened at the outset of winding with water
or an aqueous solution containing an adhesive or excipient.
17. A method as set forth in claim 16, wherein:
said water or aqueous solution is applied to said paper in the form
of stripes extending longitudinally along the length of said
paper.
18. A method for manufacturing said coreless paper roll as set
forth in claim 15, wherein:
said paper roll comprises toilet tissue.
19. A method for manufacturing a coreless paper roll as claimed in
claim 15, wherein the teeth of the gear-shaped winding shaft are
parallel to the axis of the shaft.
20. A method for manufacturing a coreless paper roll as claimed in
claim 11 or 19 wherein when the paper is wound on said winding
shaft, the paper is moistened at the outset of winding with water
or an aqueous solution containing an adhesive or excipient.
21. A method for manufacturing a coreless paper roll as claimed in
claim 15, wherein the teeth of the gear-shaped winding shaft are
helical with respect to the shaft, and at the completion of winding
the paper roll, the winding shaft is removed from the roll while
being rotated.
22. A method for manufacturing a coreless paper roll as claimed in
claim 12 or 21 wherein when the paper is wound on said winding
shaft, the paper is moistened at the outset of winding with water
or an aqueous solution containing an adhesive or excipient.
Description
FIELD OF THE INVENTION
This invention relates to a toilet paper roll and a method for
manufacturing the same. The toilet paper roll according to this
invention is coreless but nevertheless has a center hole through
which a roll supporting stem can be inserted to rotatably support
the roll on a holder.
BACKGROUND OF THE INVENTION
Generally, a toilet paper roll is manufactured by mounting a
slender tubular core such as a paper tube on the winding shaft of a
toilet paper manufacturing machine, winding toilet paper on the
core to a fixed length, extracting the winding shaft from the roll
of toilet paper on the core, and cutting the roll of toilet paper
into a number of toilet paper rolls of a fixed width.
Alternatively, a toilet paper roll may be manufactured by winding a
long strip of toilet paper of a fixed width on a tubular core of
the same width as the toilet paper. In the toilet paper roll thus
obtained, a center hole is secured by means of the tubular core, so
that the roll can be rotatably held in position within a toilet
paper holder by inserting a roll supporting stem through the
tubular core and causing this stem to be supported at the opposed
ends thereof on the holder.
However, the manufacturing cost of the toilet paper roll increases
by the cost of the paper tube and in addition, when the toilet
paper is used up, the core remains, sometimes resulting in
inconveniences as, for example, the core is thrown into the toilet
bowl and stops up the toilet.
To this end, coreless toilet paper rolls and methods for the
manufacture thereof have been proposed in Japanese Patent
Publication Nos. 42-6007 and 55-11100, and Japanese Utility Model
Publication No. 54-43963. These methods comprise loosely winding at
the outset a sheet of toilet paper on a circular winding shaft of a
small diameter in a toilet paper roll manufacturing machine, then
tightly winding the toilet paper till the paper is terminated,
extracting the winding shaft to form the roll of toilet paper, and
cutting the roll of toilet paper into suitably sized rolls of a
predetermined width. In this case, because the toilet paper is
loosely wound at the outset, the winding shaft can easily be
extracted. In the center of the toilet paper roll thus
manufactured, a hole is formed by extracting the winding shaft, and
a small diameter stem is inserted therethrough thereby allowing the
roll to be rotatably supported on the holder. However, since the
toilet paper is loosely wound at the beginning as described above,
the hole collapses and almost disappears under the pressure on the
roll when the long roll of toilet paper is cut into short rolls.
Therefore it becomes difficult to insert a shaft into the hole in
order to support the roll on a holder. Moreover, the absence of a
center hole makes the appearance of such roll deviate from the
commonly accepted concept of "toilet paper" thus reducing its
commercial value.
OBJECT OF THE INVENTION
It is an object of the present invention to provide a coreless
toilet paper roll having a center hole for receiving the
roll-supporting stem of a holder and a method for the manufacture
of such a roll.
SUMMARY OF THE INVENTION
To accomplish the object described above according to the present
invention, there is provided a coreless toilet paper roll
comprising an approximately polygonal center hole which is formed
by means of cornered or roundish constrictions extended radially,
and inwardly bulged portions each formed between the adjacent
constrictions. The center hole of the toilet paper roll is ensured
against collapse by the radially extended constrictions and the
bulged portions.
The toilet paper roll according to the present invention is
manufactured by the steps of winding toilet paper on a winding
shaft having the cross-sectional shape of a polygonal or of a
toothed wheel to obtain a roll of toilet paper on the winding
shaft, and extracting the winding shaft from the winding of toilet
paper thereby forming the center hole into a shape similar to the
winding shaft and then causing the straight-line portions between
adjacent angled portions corresponding to the corners on the outer
surface of the winding shaft to be bulged inwardly to form cornered
or roundish constrictions between the adjacent angled portions.
In the toilet paper roll, when the toilet paper is tightly wound
under pressure on the winding shaft having corners or teeth on its
outer surface and the winding shaft is extracted after completion
of winding, the straight-line portions between the angled portions
formed by the corners or teeth of the winding shaft are inwardly
bulged by centripetal pressure in the roll resulting from the tight
winding of the paper on the winding shaft. The adjacent bulged
portions press onto one another to maintain an asterisk-shaped
center hole which does not collapse. The so-formed center hole
allows the roll to be held more firmly on the holder stem than is
possible with circular center hole formed by loose winding.
Since no paper tube is used as the core of the toilet paper roll,
the roll can be reduced in cost and it is possible to avoid the
various inconveniences caused by the core which remains after the
toilet paper is used up.
Since the winding shaft on which the toilet paper is wound to
obtain the roll according to this invention is polygonal in shape,
when the winding shaft is rotated with a pressure roller in contact
therewith, vibration and noise occur at the outset of winding. To
eliminate these, the corners or teeth on the winding shaft may be
arranged helically in the axial direction, thereby enabling the
toilet paper to be smoothly wound on the shaft.
In addition, in order to completely prevent the inner peripheral
surface of the center hole of the toilet paper roll from being
deformed, water or a solution containing an adhesive can be applied
to the toilet paper at the outset of winding on the winding shaft,
whereby the center hole may be completely secured.
BRIEF DESCRIPTION OF THE DRAWINGS
Other objects and features of the present invention will be
apparent from the ensuing detailed description in connection with
the accompanying drawings, wherein:
FIG. 1 is a side view of a conventional coreless toilet paper
roll.
FIG. 2 is a side view of one example of a cutter for the toilet
paper roll.
FIG. 3 is a plan view of the same.
FIG. 4 is a side view of one preferred embodiment of a toilet paper
roll according to the present invention.
FIG. 5 is a schematic view showing the state of winding of toilet
paper in one embodiment of the present invention.
FIG. 6 illustrates the state of winding of toilet paper on the
winding shaft shown in FIG. 5 to form a roll.
FIG. 7 is a side view of a toilet paper roll in accordance with a
further embodiment of the present invention.
FIG. 8 is an explanatory diagram of a winding shaft used in the
manufacture of the roll of FIG. 7.
FIG. 9 is an explanatory diagram of a winding shaft and the
manufacture of the roll in another embodiment of the present
invention.
FIG. 10 is an explanatory diagram of a winding shaft and the
manufacture of the roll in still another embodiment of the present
invention.
FIG. 11 is an explanatory diagram of a winding shaft and the
manufacture of the roll in another embodiment of the present
invention.
FIG. 12 schematically illustrates the surface driving winding
system to which the present invention is applied.
FIG. 13 schematically illustrates a further surface driving
system.
FIGS. 14(A) and 14(B) are respectively a front view and a side view
showing one embodiment of the winding shaft in accordance with the
present invention.
FIGS. 15(A) and 15(B) are respectively a front view and a side view
showing another embodiment of the winding shaft in accordance with
the present invention.
FIGS. 16(A) and 16(B) schematically illustrate the beginning and
termination of winding in the case where a moistening device is
used in accordance with one embodiment of the present
invention.
FIG. 17 schematically illustrates a roll obtained by moistening the
toilet paper at the outset of winding.
FIG. 18 schematically illustrates another embodiment using the
moistening device.
FIG. 19 is a plan view of a strip of toilet paper showing the
pattern of moistening by the moistening device shown in FIG.
18.
FIG. 20 schematically illustrates still another embodiment using
the moistening device.
DESCRIPTION OF THE ILLUSTRATED EMBODIMENTS
The present invention relates to a coreless toilet paper roll
having a firm center hole into which a holder stem is inserted to
support the roll thereon and a method for the manufacture
thereof.
FIG. 1 illustrates a side view of a conventional coreless toilet
paper roll. A sheet of toilet paper is wound to a fixed length on a
circular winding shaft of a small diameter. After the toilet paper
is completely wound on the shaft, the shaft is extracted to obtain
the roll body 1 having a center hole 1'. The roll body 1 is set on
a cutting machine where it is cut into rolls by swinging cutting
discs 3 disposed on a rotary shaft 2 at regular intervals, as
illustrated in FIGS. 2 and 3. The center hole 1' made by extracting
the winding shaft collapses and almost disappears due to the
pressure of the cutting discs 3 on the roll body 1. The rotary
shaft 2 is pivotally supported at both free ends by arms 4 and is
driven by a chain transmission means 5 which is trained between a
pivot 4' and one end of the rotary shaft 2. The arm 4 is pivotally
swung about the pivot 4' by means of an air cylinder 6. The body 1
is laid on cradles 7 which are aligned at intervals above the bed
of the cutting machine so as to be positioned between the
respective cutting discs 3.
One example of the toilet paper roll 1 according to the present
invention is illustrated in FIG. 4. The roll body 1 has a center
hole 9 of an approximately asterisk shape and of a size large
enough to receive the stem of a toilet paper holder or the like.
The principle of the method for manufacturing such a paper roll 1
will be disclosed hereinafter with reference to FIG. 5. A sheet of
toilet paper P is wound around a non-circular winding shaft 8
mounted on the toilet paper manufacturing apparatus while rotating
the winding shaft 8 along with a riding roller 10 which is pressed
toward the shaft 8 to form a roll of toilet paper having the
required number of turns as illustrated in FIG. 6. Thereafter, the
winding shaft 8 is extracted from the roll of toilet paper which is
then cut into short rolls 1 by a cutting device as illustrated in
FIGS. 2 and 3. The winding load exerted on the toilet paper while
it is being wound on the shaft 8 is constant from the beginning to
the end of the winding of the paper, as is the case in the
conventional winding method for a toilet paper roll having a core.
The load may, of course, be gradually or stepwisely reduced with
increasing diameter of the roll. When the regular hexagonal winding
shaft 8 is extracted from the roll of toilet paper after the
winding is completed, the remaining center hole is immediately
constricted and stabilized by the force by which the paper of the
roll has obtained by winding under load. Namely, this force acts to
bulge portions of the roll towards the center (centripetal force)
in such a manner that the inner surface of the center hole, except
for the angled portions 9b formed by the corners on the outer
surface of the winding shaft 8, that is, straight-line portions 9a
corresponding to the sides 8a of the shaft 8 are slightly bulged
inwardly in an arcuate shape. As a result, a hole 9 is positively
retained. In such a toilet paper roll having a circular cross
section, the radial length R.sub.1 from the apex of each angled
portion 8b of the winding shaft to the outer circumference thereof
is smaller than the radial length R.sub.2 from each side 8a of the
winding shaft to the outer circumference thereof. Therefore, since
the paper layers are equal in number at R.sub.1 and R.sub.2, the
paper density is higher at R.sub.1 than at R.sub.2. Thus, the inner
circumferential portion of the toilet paper being wound on the
winding shaft is dented at each corner 8b of the winding shaft 8 to
form the angled portions 9b. Even when the winding shaft 8 is
extracted from the roll, their angled portions 9b keep their
position, and each side portion 9a which is formed by a side 8a of
the winding shaft and is low in winding density becomes bulged
inwardly by the centripetal force of the roll. Consequently, the
center hole 9 of the roll 1 is formed in the shape of an
asterisk.
For example, when a regular hexagonal iron winding shaft 8
measuring 20 mm between opposite corners and 17 mm between opposite
sides was used to manufacture a roll 1, the length between the
constricted portions 9b of the center hole 9 of the roll 1 was
about 15 mm, which is smaller by a mere 25% than the diagonal
length of 20 mm of the winding shaft, whereas the length between
the bulged tops of the inner circumferential portion 9a was about
8-9 mm which is smaller by 50% than 17 mm between opposite sides of
the winding shaft.
Thereafter, in cutting the roll of toilet paper into small rolls
with a cutting device, the hole 9 was not caused to collapse by the
force of the cutting edge as it passed through the high density
portion at the constricted portions 9b. The amount of deformation
was so slight that a circular shaft of up to about 10 mm in
diameter could easily be inserted therethrough to permit the roll
to be rotatably supported on a holder. It should be noted that if
the circular stem has one end or both ends thereof formed to have a
somewhat smaller diameter for easy insertion, a stem of even about
15 mm in diameter can be inserted through the hole 9. as the hole 9
is somewhat expanded outwardly.
FIG. 7 is a side view showing a further embodiment of the toilet
paper roll in accordance with the present invention. In this case,
as shown in FIG. 8, eight circularly sectioned grooves 12a 2 mm
deep and 5.5 mm wide, are formed in the outer circumference of a
round iron bar having a diameter of 20 mm. The grooves 12a are
equally spaced about 2 mm from each other to make a winding shaft
12 having a cross-sectional shape resembling a gear, on which
toilet paper is wound. The winding shaft is extracted after winding
and the resulting roll is cut into short rolls by the cutter
device. The winding load can be maintained constant from the
beginning to the end in the customary manner or can be gradually or
stepwisely reduced as the diameter increases, as described in
connection with the previous embodiment.
Also, in this case, the radial length R.sub.1 from the apex 12b
between the grooves 12a to the outer circumference of the toilet
paper roll is slightly smaller than the radial length R.sub.2 from
the surface of the groove 12a to the outer circumference and the
density of the paper is higher by such amount. The inner
circumferential portion of the toilet paper is forced onto the
apexes 12b on the outer circumference of the winding shaft and
wound thereabout, and the portions 13b in contact with the apexes
12b become radially depressed into a tooth profile as in the shaft
12. Accordingly, when the winding shaft 12 is removed, the
remaining hole 13 shrinks but the centripetal pressure which causes
the shrinkage acts mainly on the portions 13a which were in contact
with the grooves of the winding shaft and said portion becomes
bulged inwardly. After removal of the winding shaft, the diagonal
length between the portions 13b depressed into a radial tooth
profile is about 16 mm which is smaller by 20% than the 20 mm
diameter of the winding shaft whereas the length between the bulged
tops of the portions 13a is about 12 mm, which is smaller by 40%.
Even if the paper roll is cut into short rolls by the cutter
device, the hole 13 does not collapse under the force of the
cutting edge at the portion 13b having a high density. Thus since
the deformation is slight, a circular shaft of up to about 12 mm
can be easily inserted therethrough and rotatably mounted on the
holder.
In the FIG. 7 embodiment, the portion 13b depressed into a tooth
profile is present between the inwardly bulged portions 13a and
distanced from the adjacent portions 13a, whereas in the embodiment
shown in FIG. 4, the inwardly bulged portion 9a compresses the part
of the constricted portion 9b previously in contact with the corner
of the winding shaft with those adjacent each other being in
contact with each other. The center hole formed by the bulged
portions as shown in FIG. 4 is less deformed than that in FIG.
7.
FIG. 9 shows a modified form of the winding shaft 12 as having a
nearly square cross section whose sides are bowed inwardly. FIG. 10
shows a winding shaft 12 having a cross section resembling a
pentagon, and FIG. 11 shows a winding shaft having a cross section
resembling a hexagon.
By manufacturing a toilet paper roll without using a paper tube as
a core, it is possible to prevent the center hole from losing its
shape under external force applied to the roll or self-centripetal
force, and it becomes possible to obtain a toilet paper roll of the
same quality as the conventional roll, which has a center hole
averaging 5 to 10 mm in diameter.
The method of manufacturing such a toilet paper roll, as shown in
FIG. 5, is generally called "the center driving system". Besides
this method, there are so-called surface driving systems. One of
the surface driving systems is composed of a winding shaft 8
arranged between a pair of rollers 14 as shown in FIG. 12. Another
of the systems uses a winding shaft 8 arranged between endless
belts 15 stretched in the form of the letter V or the letter X as
shown in FIG. 13. In either case, a riding roller 10 rides on the
winding shaft in order that the toilet paper P may be wound about
the winding shaft with a predetermined winding tightness. The
pressure applied by the riding roller 10 may be simply that of its
own weight or that of its own weight plus that of an additional
weight or the force of a piston. The riding roller is in direct
contact with the winding shaft from above at the beginning. Once
toilet paper is wound around the shaft, the riding roller comes
into contact with the shaft through the wound toilet paper and is
gradually raised with increase in winding volume of the toilet
paper.
In this case, the winding shaft has a polygonal cross section like
a gear. When the cornered portions corresponding to the teeth of
the gear are parallel to the axis of the winding shaft, the riding
roller bounds over the winding shaft due to the non-cylindrical
configuration of the winding shaft until the toilet paper is amply
wound on the winding shaft to assume a nearly cylindrical contour.
In the case of the surface driving system, not only the riding
roller but the winding shaft itself bounds over the rollers 14 or
belts 15. As a result, there is a possibility that the desired
winding tightness of the toilet paper is not obtained, or the
winding shaft is displaced from the center, thereby causing the
center hole formed by extracting the winding shaft to be made
eccentric. Besides, it may happen that the toilet paper is torn
widthwise during the winding, resulting in waste.
In order to overcome these problems, the present invention provides
an arrangement wherein the corners of a polygonal winding shaft are
spirally formed in the axial direction to minimize bounding of the
riding roller or the winding shaft. This embodiment will now be
described.
FIGS. 14(A) and 14(B) show one example of a winding shaft having a
polygonal section in accordance with the present invention.
Reference numeral 16 denotes a winding portion on which toilet
paper of the required length is wound, and the axial length of the
winding portion is determined to be somewhat longer than the width
of the toilet paper to be wound, normally, about 2 m. A cylindrical
spindle 17 is extended from either end of the winding portion 16.
In case of the center driving system, one or both of the spindles
17 are detachably set on bearings of the winding machine to impart
a rotational power thereto. In case of the surface driving system,
the spindle 17 is set on the winding machine such that the shaft
may be moved upwardly from the roller 14 or belt 15 as the winding
takes place but one or both sides thereof can be detached from the
winding machine.
The sectional shape of the winding portion 16 herein employed is a
regular hexagon, and the position of each corner 18 is offset by
90.degree. between one end 16a and the other end 16b of the winding
portion. That is, each corner 18 is formed helically with a 1/4
pitch. The helical pitch is not limited to 1/4 relative to the full
length of the winding portion, but it is preferred to determine the
pitch by choosing 360.degree./n where n is the number of corners,
such that the riding roller may rest on a part of one of corners at
all times, and that, in the case of the surface driving system
winding machine, the winding shaft may come into contact with the
roller 14 or belt 15 at a part of one of corners at all times. For
example if the winding portion is a regular hexagonal, the pitch
will be 60.degree., namely, 1/6. It is of course possible to make
the pitch smaller than 60.degree.. For example, in the case of a
regular octagon, 45.degree. or 1/8 pitch will suffice since the
jumping amount is considerably reduced as compared with the prior
art in which the corner is parallel to the axis.
The same is true of the case of the winding shaft shown in FIGS.
15(A) and 15(B) in which the winding portion has a gear shaped
section. In this embodiment, twelve teeth (or grooves) 19 are
formed circumferentially in equally spaced relation helically with
1/6 pitch, which is two times of 360.degree./12=30.degree.=1/12
pitch.
Most preferably, a pitch which is two or three times 360.degree./n
as described hereinbefore is used as in such case the riding roller
is always in contact with a plurality of corners to effect winding
similar to a winding shaft with a cylindrical outer surface so that
bounding of the riding roller (in the case of surface driving
system, bounding of the winding shaft) does not occur.
As described hereinbefore, in accordance with the present
invention, the aforementioned disadvantages may be eliminated by
minimizing the bounding of the riding roller or the winding shaft
itself from the outset of winding or effecting winding of the
toilet paper without producing bounding at all. Moreover, inner
circumference of the wound toilet paper is given the impression of
the helical corners or teeth so that when the winding shaft is
removed the portions between the portions indented by the corners
or teeth are inwardly bulged to maintain an inner circumferential
configuration thereof.
In removing the winding shaft, it is necessary to pull it while
rotating it along the helices formed by the corners or teeth. To
this end, the pitch of the helix is determined in consideration of
the amount of rotation required in removal, and in view of the ease
of removal, the pitch will be the amount obtained in consideration
of rotation of the winding shaft, for example, two to three times,
preferably within one rotation, that is, within one pitch.
Toilet paper rolls can be manufactured by one method which
comprises winding a wide sheet as it is and then, after winding,
cutting the resulting long roll into short rolls of predetermined
length or by another method which comprises winding the wide sheet
on a series of winding shafts while simultaneously slitting the
sheet to a predetermined product width (for example, see Japanese
Patent Publication No. 42-6007). The present invention may be
applied to either of the aforesaid methods.
As described hereinbefore, in the present invention, toilet paper
in wound about a winding shaft of polygonal or gear-shaped section,
and after wound, the winding shaft is removed to form a toilet
paper roll having an asterisk-like center hole. In this connection,
in order to positively prevent the center hole of the roll from
losing its shape, water or an aqueous solution containing a low
concentration of an adhesive such as paste which hardens when
dried, sodium celluloseglycolate (generally called CMC) and other
excipients is applied at the outset of winding to wet the toilet
paper. As the water (or the water content of the solution) is
absorbed by the adjacent wound layers of paper during the winding,
corners similar to the corners of the winding shaft appear
distinctly in the inner circumferential portion of the toilet paper
roll. This will be described hereinafter by way of embodiments
shown in the drawings.
FIGS. 16(A) and 16(B) show an embodiment provided with a mechanism
for moistening the center of a layer of wound paper on the basis of
the winding system shown in FIG. 12 as one example.
A winding shaft 8 rides on and between driving rollers 14 and is
frictionally rotated by means of the driving rollers 14 in a state
being held by a riding roller 10 from above to wind a sheet of
toilet paper P thereabout with suitable tightness utilizing the
weight of the riding roller, an extra weight and the pressing force
of a piston as necessary. As the winding progresses, the outside
diameter of the wound roll of toilet paper increases and the
winding shaft 8 is upwardly moved away from the driving rollers 14
while raising the riding roller 10. After the toilet paper has been
wound to the required length, the winding shaft is stopped, the
riding roller moved to a standby position, and the entire winding
shaft is removed from the winding machine or one end of the winding
shaft is released from the winding machine so that it can be pulled
out of the roll of wound paper, after which the roll is cut into
smaller rolls of predetermined length.
Directly under the space between the two driving rollers 14 is
provided an upwardly directed nozzle 21 for spraying water or the
aforesaid aqueous solution towards the toilet paper P at the outset
of winding. By this spraying, the water content of the portions
sprayed is increased by 5-7% to about 25-35% over the previous dry
condition.
It is sufficient to spray the first winding or the first few
windings of the toilet paper, or to spray one or a few windings
following the first one or few windings. The spraying can be
controlled suitably and as desired by adjustment of the nozzle 21,
by use of a timer or in response to turning-on of a winding
starting switch. That is, water or aqueous solution is sprayed
through the nozzle for several seconds immediately after or several
seconds after the switch is turned on.
Normally, it takes about 15-20 seconds to wind about 65 m of toilet
paper, during which a part of the water sprayed at the outset of
winding is absorbed by the layers of dry paper in the neighborhood
to lightly moisten the inner peripheral region 20' of the wound
paper 20 (at the termination of winding, the water content is
15-20%), and the inner peripheral region 20' is tightened about the
outer circumference of the winding shaft by succeeding windings of
the toilet paper externally of the inner peripheral region. A
corner just along the corner 8b thus distinctly appears in the
portion in contact with the corner 8b of the winding shaft.
Accordingly, when the winding shaft is removed after the winding
has been completed, a corner 20b remains as it is in the inner
peripheral region of the layer of wound paper to form a toilet
paper roll as shown in FIG. 17 in which a portion 20a adjacent and
between the corners 20b is inwardly bulged similarly to the
previous embodiment 1. It should be noted that FIG. 17 shows the
sectional shape of the winding shaft in broken lines to show the
change in the inner peripheral region between the time before the
winding shaft is removed and the time after the winding shaft has
been removed.
Even if the toilet paper is not moistened at the outset of winding
as in the first embodiment, the contour of the inner peripheral
region after the winding shaft has been removed is not changed very
much. In this case, however, since the inner peripheral region of
the toilet paper roll remains dry, the fibers which consitute the
toilet paper maintain their elasticity so that the corner is less
distinct than in the case where moistening is carried out. On the
other hand, when the inner peripheral region is lightly moistened
in accordance with the present embodiment, the fibers lose their
elasticity to assume the configuration as expected whereby a
distinct corner appears. After the winding shaft has been removed,
air flows through the resulting hole to the paper while the corner
is still distinctly present.
Thus, in cutting the toilet paper roll into shorter rolls with the
cutter in the subsequent step, the corners in the inner peripheral
portion maintain their configuration in the manner as described,
and therefore they withstand the pressing force resulting from the
cutting-in of the cutter, thus producing no products in which the
inner peripheral portion is collapsed. Also, the inner portion will
not collapse even under shocks sustained when the products are
packed into corrugated carboard boxes piled one upon another in
order to prevent the boxes from breaking loose. The water content
of the inner peripheral portion is about 15-20% at the termination
of winding as described hereinbefore and is about 10-12% when the
roll is cut into shorter rolls about 10-15 minutes after the
winding shaft has been removed immediately after the termination of
winding.
When, instead of water, a low concentration aqueous solution is
sprayed as an excipient, the inner peripheral portion is solidified
as it dries and thus such solution is more effective.
FIG. 18 shows an arrangement wherein a moistening device is applied
to the surface driving system toilet paper winding machine shown in
the embodiment of FIG. 13. In this arrangement, two sets of narrow
endless belts 15 are crossed into an X-shape, a winding shaft is
arranged along the bottom of a valley 22 formed between the belts,
the winding shaft being held by the riding roller 10, and the
winding shaft is rotatably driven in one direction by the two belts
to wind toilet paper thereon. Frontwardly of the upper end of one
belt which forms the valley 22 there is arranged a coating roller
23 for applying water or the like in the form of longitudinal
stripes on the toilet paper downwardly moving into the valley while
maintaining the spacing widthwise, and a liquid supply device is
provided in which water or the like is applied to the coating
surface of the coating roller by means of a liquid supply roller 24
half of which is immersed in a vat filled with water or the like.
Then, the device is raised by means of a cylinder 25 for a
predetermined short period of time at the outset of winding, water
or the like is applied to the toilet paper by the coating roller 23
to form water stripes 26 (FIG. 19), and after the lapse of the
specified time the cylinder is moved down to disengage the device
from the toilet paper.
The amount of water used for forming the water stripes, the width
of the stripes and the spacing between the stripes are determined
such that the whole portion in the width direction is moistened
about when the stripes have moved down to the valley bottom and are
wound about the winding shaft, and care should be taken so that the
toilet paper is not cut widthwise prior to winding of the stripes
about the winding shaft.
During the course of winding, water or the like applied at the
outset of winding propagates to the wound paper in the neighborhood
to lightly moisten the inner peripheral portion and therefore, a
distinct corner just along the corner on the outer circumference of
the winding shaft appears in the inner peripheral portion and even
after the winding shaft is removed, the corner maintains its
configuration, whereby the inner peripheral portion does not
collapse.
While in this embodiment, the winding portion of the winding shaft
is in the form of the gear-shaped section having the teeth 8', it
should be appreciated that a polygonal section can be also used
similarly to the aforementioned embodiments.
The embodiment shown in FIG. 20 uses the moistening device
comprising the coating roller 23, the liquid supply roller 24, and
the like, of the embodiment of FIG. 18, in place of the nozzle 21
in the arrangement of FIG. 16. The coating roller 23 is disposed so
that it may come into contact with one of the driving rollers 14,
and the cylinder 25 is driven for a suitable period of time to
bring the coating roller 23 into contact with the driving roller 14
to thereby impart a suitable amount of water to the toilet paper P
through the roller 14. Similar effects to those of the embodiments
shown in FIGS. 16 and 18 can be attained.
In the embodiments which use these moistening devices, the number
of corners of the polygon of the winding shaft and the number of
teeth of the gear-shape section may be suitably determined
depending on the outside diameter of the winding shaft. For
example, to form an inner peripheral portion whose average inside
diameter is greater than 25 mm, the number of corners or the number
of teeth should be more than ten, preferably, 12 to 16.
As described above, if the toilet paper is lightly moistened when
it is wound, the corners formed by the corners of the outer
circumstance of the winding shaft may be distinctly produced in the
center hole of the roll to maintain the configuration of the inner
peripheral portion, and therefore even a center hole which has a
relatively large average inside diameter, larger than about 25 mm,
may be produced.
As is apparent from the foregoing, method of manufacturing a toilet
paper roll in accordance with the present invention can positively
produce a hole by removing the winding shaft after winding, and,
therefore, the shaft for mounting the roll on a holder may be
easily passed therethrough. Moreover, the toilet paper roll
produced matches the generally accepted concept of a toilet paper
roll having a hole at the center. What is more, the shape of the
hole is not a mere circle but can be variously changed depending on
the sectional shape of the winding shaft. Thus the hole itself can
also serve as a kind of ornament.
In addition, since a paper tube is not used, the products may be
manufactured at a cost lower by the price of the tube. After the
paper is used up, nothing remains so that there is no danger of
such troubles as the stopping-up of the toilet by a paper tube. If
a smaller diameter of the winding shaft is used, a longer sheet of
toilet paper, nearly twice as long as that on a conventional roll
having a tube, can be wound within the same outside diameter.
Furthermore, prior art toilet paper manufacturing machines may be
used for carrying out the method of this invention without
modification merely by replacing the winding shaft.
It is known from Japanese Patent Publication No. 42-6007 that a
broad sheet of toilet paper can be wound while slitting it into
predetermined product widths by means of a cutting roll. In this
case, there is no need to cut a long toilet paper roll into shorter
rolls as in the case where an axially long toilet paper roll is
manufactured. The toilet paper is wound directly on the winding
shaft having a circular section while slitting it to predetermined
widths, after which each short roll is removed from the winding
shaft leaving a circular hole at the center. However, this circular
hole will collapse to a semicircle under the shocks and pressure
occurring when the rolls are packed into cardboard boxes for
transportation and storage, or by the pressure of ropes or cords
used to bind stacks of the cardboard boxes to prevent them from
breaking loose. In this case, the external shape of the product
also changes. However, when the original sheet of toilet paper is
wound on the winding shaft of a polygon or gear-shaped sectional
shape while being slit to predetermined widths in accordance with
the present invention, it is possible to prevent the hole of the
inner peripheral portion and the external shape from being deformed
when the products are transported and stored. Moreover, the toilet
paper wound on the winding shaft does not press onto all parts of
the outer circumference of the winding shaft evenly as is the case
when using a circular winding shaft and thus the present winding
shaft may be removed more easily than a circular winding shaft.
Furthermore, in accordance with the present invention, the corners
or teeth provided on the winding shaft are twisted into a helical
configuration, thereby minimizing or completely preventing bounding
of the riding roller when the paper is wound on the non-circular
winding shaft. Therefore, the quality of the toilet paper roll is
not deteriorated and the occurrence of vibration and noise during
the winding can be minimized.
In addition, water or a solution containing paste or the like is
applied to toilet paper to be wound at the outset of winding or at
suitable time thereafter, whereby a center hole having polygonal or
gear-shaped corners may be secured in nearly perfect condition so
that there is no danger of the hole being pressed out of shape
during normal handling.
Obviously, many modifications and variations of the present
invention are possible in light of the above teachings. It is
therefore to be understood that within the scope of the appended
claims, the present invention may be practiced otherwise than as
specifically as described herein.
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